System and method for layer-wise proton beam current variation

ABSTRACT

Systems and methods are provided to perform efficient, automatic adjustment of cyclotron beam currents within a wide range for multiple treatment layers within the same patient and treatment session. In one embodiment, efficient adjustment is achieved by using beam current attenuation by an electrostatic vertical deflector installed in the inner center of the cyclotron. The beam current may, for example, be adjusted by the high voltage applied to the electrostatic vertical deflector. In front of each treatment the attenuation curve of the vertical deflector is recorded. Based on this attenuation curve, the vertical deflector voltage for the needed beam current of each irradiation layer is interpolated. With this procedure the beam current could be automatically adjusted in minimal time over a wide range while maintaining a high level of precision.

CLAIM OF PRIORITY

This application is a continuation of U.S. patent application Ser. No.13/224,773, filed Sep. 2, 2011 both claiming the benefit of U.S.Provisional Application No. 61/380,017, filed Sep. 3, 2010, and is alsorelated to co-pending U.S. patent application entitled “SYSTEM ANDMETHOD FOR AUTOMATED CYCLOTRON PROCEDURES,” Ser. No. 13/887,071, filedon the same day herewith and U.S. patent application Ser. No.13/225,045, filed Sep. 2, 2011. Each of these references areincorporated by reference herein in their entireties and for allpurposes.

TECHNICAL BACKGROUND

Radiation therapy (RT) is a popular and efficient method for cancertreatment, where ionizing radiation is used in an attempt to destroymalignant tumor cells or to slow down their growth. RT is often combinedwith surgery, chemotherapy, or hormone therapy, but may also be used asa primary therapy mode. Radiation therapy is most commonly administeredas external beam RT, which typically involves directing beams ofradiated particles produced by sources located externally with respectto the patient or subject to the afflicted treatment area. The beam canconsist of photons, electrons, protons or other heavy ions. As the beamtravels through matter (e.g., the subject), energy from the ionizingradiation is deposited along the path in the surrounding matter. Thisenergy is known as “dose,” and is used to measure the efficacy andaccuracy of a radiation beam. Malignant cells are damaged along the pathof radiation beam during the RT. Unfortunately, the damage from theradiation is not limited to malignant cells and may be incurred by anyinterceding or adjacent cells. Thus, the dosage of radiation to healthytissues outside the treatment volume is ideally minimized to avoid beingcollaterally damaged.

Proton therapy is one type of external beam radiation therapy, and ischaracterized for using a beam of protons to irradiate diseased tissue.The chief advantage of proton therapy over other particle-basedtherapies is the ability to administer treatment dosages threedimensionally, by specifying the depth (i.e., penetration) of appliedradiation, thereby limiting the inadvertent exposure of untargeted cellsto the potentially harmful radiation. This enables proton therapytreatments to more precisely localize the radiation dosage when comparedwith other types of external beam radiotherapy. During proton therapytreatment, a particle accelerator, such as a cyclotron, is used togenerate a beam of protons from an internal ion source located in thecenter of the cyclotron. Typically, a cyclotron is located in a locationremote from the target treatment room. The generated protons aredirected, via magnets, through a series of interconnecting tubes (calledthe beamline), and applied to a subject in a target treatment room.

Generally speaking, cyclotrons generate a proton beam at a fixed energyfor the duration of a proton therapy treatment. During typical protonradiation treatments however, irradiating a tumor often requiresirradiating an entire volume (a tumor, for example) at different depthswithin a patient or treatment subject. These depths, which may bereferred to in discrete units as layers, naturally correspond todifferent “optimal” energy levels. Since cyclotrons operate only at afixed energy during a treatment session, irradiating different depthscan become problematic. Conventional methods for irradiating a volumeare performed by applying a single beam current, and begin by targetingthe furthest depth within a patient or subject. For differing depths, acomponent (such as a carbon filter or “degrader”) is inserted into thepath of the extracted beam at some distance from the cyclotron. Thedegrader material reduces the speed of the particles (and thereby thebeam energy). Every time the proton beam's energy is changed thisresults in a new “layer” within the patient or target receivingtreatment.

However, the degrader material also reduces the density and number ofparticles comprising the beam (e.g., the “beam intensity”) thatcontinues past the degrader. In order to achieve proper dose rates foreach layer, this may be compensated by increasing the beam intensitythat the cyclotron delivers to the degrader input. Unfortunately, usingconventional techniques the change of beam intensity within a cyclotroncan take a significant amount of time.

As a result, proton therapy according to conventional operatingtechniques is generally limited to relatively simple treatment plans,which even then may require exceptionally and inefficiently longirradiation times. In some cases, if the extracted beam current must befrequently varied according to a multiplicity of layers requiringtreatment for example, new, practically separate treatment plans wouldneed to be devised which would likely lead to even more delays andinefficiencies. Moreover, due to the complexity of the underlyingmachines, their operating and maintenance procedures, and the gravity ofthe corresponding medical procedures, highly trained and skilledoperators are needed to perform the calculations and actions necessaryto make adjustments to a proton beam current. Naturally, this can resultin further inefficiency, delays or even potential hazards if qualifiedoperators are not available.

SUMMARY

This Summary is provided to introduce a selection of concepts in asimplified form that is further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used to limit the scope of the claimed subject matter.

To overcome the difficulties inherent in traditional cyclotron beamadjustment methods, new techniques for automating these procedures areherein provided. According to one aspect of the invention, a system andmethods are provided to perform an efficient adjustment of cyclotronbeam currents within a wide range for each treatment layer. In oneembodiment, efficient adjustment is achieved by using beam currentattenuation by a beam path modulator (such as an electrostatic verticaldeflector) installed in the inner center of the cyclotron. The beamcurrent may, for example, be adjusted by applying a high voltage to theelectrostatic vertical deflector. The protons will be deflected by theelectrical field (generated by the applied voltage) to a verticalcollimator. Due to the applied voltage, only a dedicated amount ofprotons will pass the vertical deflector system. At the beginning ofeach treatment the attenuation curve of the vertical deflector isrecorded. Based on this attenuation curve, the vertical deflectorvoltage for the needed beam current of each irradiation layer isinterpolated. With this procedure, the beam current could beautomatically adjusted in minimal time over a wide range whilemaintaining a high level of precision.

According to one embodiment, a proton radiation treatment is prepared byfirst setting the maximum beam current to reach the nearest desireddepth within the patient (e.g., by proper positioning of moveable phaseslits in the cyclotron), subsequently, the beam current is attenuated byadjusting the voltage of an electrostatic vertical deflector to acquirea plurality of data points, thereby generating an interpolation tablecontaining vertical deflector voltages versus resulting extracted beamcurrents. Using this interpolation table the appropriate verticaldeflector settings are determined from the desired beam currentsetpoints, and adjustment of the extracted beam current can be performedautomatically and rapidly, thereby advantageously extending the abilityto provide more complex treatment plans while drastically reducing theoverall irradiation time.

The maximum beam current for each patient treatment is adjusted by meansof two movable phase slits based on an automatically generated look-uptable. Beam current adjustment starts by setting the slit widths todefined values. The slits are then opened and allow a precise tuning ofthe maximal beam current in the range between for example 1 nA to 800nA. After the adjustment of the phase slits the dependency of the beamcurrent on the voltage of the vertical deflector is recorded. Accordingto some embodiments, the complete sequence can take approximately twentyseconds. Based on this suppression curve, the beam current can besubsequently changed within milliseconds over a wide dynamic range bychanging the voltage setting of the vertical deflector during theirradiation.

BRIEF DESCRIPTION OF DRAWINGS

The accompanying drawings, which are incorporated in and form a part ofthis specification, illustrate embodiments of the invention and,together with the description, serve to explain the principles of theinvention:

FIG. 1 depicts a diagram of an exemplary proton accelerator, inaccordance with various embodiments of the claimed subject matter.

FIG. 2 depicts an expanded-view diagram of an exemplary protonaccelerator, in accordance with various embodiments of the claimedsubject matter.

FIG. 3 depicts an illustration of the central region of an exemplaryproton accelerator, in accordance with various embodiments of theclaimed subject matter.

FIG. 4 depicts an illustration of an example non-spiral trajectorywithout influence from an electric field generated by an electrostaticvertical deflector system in an exemplary proton accelerator, inaccordance with embodiments of the claimed subject matter.

FIG. 5 depicts an illustration of an example non-spiral trajectoryinfluenced by an electric field generated by an electrostatic verticaldeflector system in an exemplary proton accelerator, in accordance withembodiments of the claimed subject matter.

FIG. 6 depicts a flowchart of a method of automatically generatingmultiple extracted beam currents in an exemplary proton accelerator, inaccordance with embodiments of the claimed subject matter.

DETAILED DESCRIPTION

Reference will now be made in detail to several embodiments. While thesubject matter will be described in conjunction with the alternativeembodiments, it will be understood that they are not intended to limitthe claimed subject matter to these embodiments. On the contrary, theclaimed subject matter is intended to cover alternative, modifications,and equivalents, which may be included within the spirit and scope ofthe claimed subject matter as defined by the appended claims.

Furthermore, in the following detailed description, numerous specificdetails are set forth in order to provide a thorough understanding ofthe claimed subject matter. However, it will be recognized by oneskilled in the art that embodiments may be practiced without thesespecific details or with equivalents thereof. In other instances,well-known methods, procedures, and components, have not been describedin detail as not to unnecessarily obscure aspects and features of thesubject matter.

Portions of the detailed description that follows are presented anddiscussed in terms of a method. Although steps and sequencing thereofare disclosed in figures herein (e.g., FIG. 6) describing the operationsof this method, such steps and sequencing are exemplary. Embodiments arewell suited to performing various other steps or variations of the stepsrecited in the flowchart of the figure herein, and in a sequence otherthan that depicted and described herein.

Exemplary Proton Accelerator

With reference now to FIG. 1, an illustration of an exemplary protonaccelerator 100 is depicted, in accordance with one embodiment. In oneconfiguration, the proton accelerator 100 may be implemented as acyclotron. In further embodiments, the cyclotron may be, for example, acompact four sector isochronous cyclotron incorporating asuperconducting main coil. As depicted, the superconducting main coilmay be housed in a central chamber 101, in which particles of agenerated proton beam from an ion source are accelerated on radiallyincreasing trajectories. In an exemplary configuration, the cyclotronoperates with a beam energy of 250 MeV, and capable of generating amaximum beam current of about 800 nA and the typical extractionefficiency is 80%.

With reference now to FIG. 2, an illustration of an expanded-viewdiagram of an exemplary proton accelerator 200, in accordance withvarious embodiments of the claimed subject matter. The exemplary protonaccelerator 200 may, for example, be implemented as the cyclotrondescribed above with reference to FIG. 1. As depicted, FIG. 2 depictsthe upper portion of a cyclotron 200 with a raised top 207 (typicalduring the performance of maintenance, for example). A beam of protonsis generated in a central chamber 209 by an ion source 203, and radiallyaccelerated by electrical fields of a radio frequency (RF) drivensub-system and guided to the extraction radius in a spiral form by themagnetic field induced by the superconducting main coil (depicted, inpart, as 205).

FIG. 3 depicts a close-up illustration of a portion of the centralchamber 300 (e.g., central chamber 209) in an exemplary protonaccelerator (e.g., cyclotron 100 and 200), in accordance with variousembodiments of the claimed subject matter. The portion of the centralchamber 300 depicted in FIG. 3 includes an internal ion source 301, anbeam path modulator (e.g., electrostatic vertical deflector plate 303and vertical collimator plate 305). According to one embodiment, duringa proton therapy treatment session, a proton beam emanates as a streamor bursts of protons from the ion source 301, the stream of protons isaccelerated by electrical fields of the RF system and guided to theextraction radius in a spiral form via the magnetic field in the centralchamber 300 produced by magnetic coils (e.g., magnetic coils 205).

The produced proton beam is threaded through one or more beam currentmodulators (e.g., phase slits 306), resulting in an extracted protonbeam having a corresponding beam current. As presented, the phase slits306 include apertures through which the proton beam travels. In oneembodiment, the size of the aperture of a phase slit 306 is ofsufficient size to allow a generated proton beam to traverse completelyunimpeded. According to alternate embodiments, the size of the apertureof the phase slit 306 is less than that of a complete proton beam, suchthat at least a portion of any generated proton beam is absorbed by thematerial of the phase slit 306 when the proton beam is travellingthrough the aperture.

Tuning the proton beam (and by extension, the beam current of anextracted beam) may be performed by producing a voltage in theelectrostatic vertical deflector 303, thereby producing an electricfield. The properties imparted by the electric field affect theparticles comprised in the beam of protons, and is capable ofinfluencing the trajectory of the produced proton beam. A strongerelectric field produces a greater influence, and thus, the proton beamis capable of being aimed to the extent that the trajectory of theproton beam is at least partially directed into (and thus, interceptedby) the vertical collimator 305 by running varying voltages through theelectrostatic vertical deflector 303. For example, in one embodiment, amaximum beam current may correspond to little or no voltage in theelectrostatic vertical deflector 303, thereby leaving most if not all ofthe produced beam through the aperture unimpeded.

The transmitted beam of the vertical deflector and collimator systemswill be guided to the phase slits 306. According to one embodiment, theopening widths of the phase slits are variable and a portion of theproton beam could be stopped by this measure. If the apertures of thephase slits are completely open, the transmitted beam by the verticaldeflector and collimator systems and the extracted beam may haveapproximately the same beam current (only influenced by the extractionefficiency of the cyclotron). The magnitude of the electric field of thevertical deflector may be controlled by running smaller or largervoltages through the electrostatic vertical deflector 303. The portionof the proton beam that travels through the apertures of the verticalcollimator and the phase slits has a decreased beam current with anintensity lowered by an amount which corresponds to the portion of theproduced proton beam intercepted by the non-aperture portion of thevertical collimator and the phase slits.

With reference now to FIG. 4, an illustration 400 of an exampletrajectory 401 of a proton beam without being influenced by an electricfield generated by a electrostatic vertical deflector 403 in anexemplary proton accelerator is depicted, in accordance with embodimentsof the claimed subject matter. As presented in FIG. 4, an electrostaticvertical deflector 403 and a vertical collimator 405 with an apertureare disposed in a cyclotron (e.g., cyclotron 100 and 200). In furtherembodiments, the electrostatic vertical deflector 403 and verticalcollimator 405 are disposed within a central chamber (e.g., centralchamber 209) of the cyclotron. A generated proton beam (e.g., emanatingfrom an ion source such as ion source 203) with sample trajectory 401travels through an area adjacent to an electrostatic vertical deflector403, and towards (and through) the vertical collimator 405. As shown,with little (or no) influence by an electric field generated by theelectrostatic vertical deflector 403, the generated proton beam is ableto travel directly through the aperture of the vertical collimator 405unimpeded, losing little to no beam intensity (and thus, maintaining aconsistent beam current) in the process. As presented, the sampletrajectory 401 may, for example, correspond to a maximum desired beamcurrent for a proton treatment therapy.

Conversely, and with reference now to FIG. 5, an illustration 500 of anexample trajectory 501 of a proton beam influenced by an electric fieldgenerated by a electrostatic vertical deflector 503 in an exemplaryproton accelerator is depicted, in accordance with embodiments of theclaimed subject matter. As presented in FIG. 5, the electrostaticvertical deflector 503 and vertical collimator 505 with an aperture andcorresponding to their equivalents in FIG. 4 (electrostatic verticaldeflector 403 and a vertical collimator 405, respectively) are disposedwithin a central chamber (e.g., central chamber 209) of a cyclotron(e.g., cyclotron 100 and 200). According to one embodiment, running avoltage through the electrostatic vertical deflector 503 creates anelectric field 507. A generated proton beam (e.g., emanating from an ionsource such as ion source 203) with sample trajectory 501 travellingthrough the electric field 507 towards (and through) vertical collimator505 will be impacted by the properties of the electric field 507. Anelectric field with sufficient magnitude is capable of altering thetrajectory of the proton beam. As shown, with sufficient influence by anelectric field generated by the electrostatic vertical deflector 503,the generated proton beam can be directed towards the non-apertureportion of the vertical collimator 505, having the particles of the beamimpeded by the non-aperture portion of the vertical collimator 505 beingabsorbed by the material of the vertical collimator 505, and losing beamintensity proportional to the portion of the beam that was obstructed(and thus, decreasing the beam current) in the process. As presented,the sample trajectory 501 may, for example, correspond to a desired beamcurrent less than the maximum beam current (e.g., shallower “layers” ina target subject) for a proton treatment therapy.

Proton Beam Trajectory Tuning

During medical operation, the control and oversight of a generatedproton beam may be completely managed by a higher level control systemoperating in a computer system (thus not necessitating manualoperation). This management may include, for example, the requests fordesired beam currents. During operation of the cyclotron, adjustments tothe generated beam may be performed to produce varying extracted beams.According to one embodiment, a proton radiation beam is generated atstep 601. The generated proton radiation beam may have an initial beamcurrent set to the maximum beam current calculated to reach the neededintensity for the lowest desired depth for a radiation treatment plan(e.g., by proper positioning of moveable phase slits in the cyclotron).The maximum beam current for each treatment is adjusted by means of twomovable phase slits (the position and/or aperture size of phase slitsmay, for example, be calculated by manually or automatically referencinga table of configuration data, for example). Beam current adjustment maybegin by setting the phase slit widths to pre-defined values. The slitsare then opened to allow passage of the generated beam at step 603, andprecise tuning of the beam current (e.g., typically within the rangebetween 1 nA to 800 nA) may be performed by adjusting the positions ofthe phase slits.

The tuning of the beam current is performed by a multi-step processwhich begins by measuring extracted beam currents under varyingcircumstances, performed at step 605. After the adjustment of the phaseslits, varying voltages are generated in a vertical deflector, producingelectric fields of varying magnitudes. The generated electric fieldsinfluence the trajectory of the produced beam traveling through thevertical collimator. For example, if the magnitude of the field issufficient to affect the trajectory such that a portion of the protonbeam's path is obstructed by the non-aperture portion of the verticalcollimator, the resultant beam current is attenuated by a correspondingamount. The resulting suppressed beam current is monitored and trackedfor varying pre-determined data points (e.g., the radial positions ofthe phase slits, the voltage in the vertical deflector), and thecorrespondence of the extracted beam and the voltage of the verticaldeflector is measured and recorded (e.g., at a local or remotely locatedcomputing device). According to some embodiments, five or more datapoints (e.g., configurations) may be tracked and monitored for atreatment during the tuning process. In further embodiments, the five ormore data points may be distributed in the range between the maximumdesired beam current and the minimum desired beam current for a protontreatment therapy session.

The data is then analyzed at step 607 to determine the correspondencebetween an extracted beam current and a voltage of the verticaldeflector required to produce a beam having the extracted beam current(e.g., by extrapolating the data points to approximate a curve). Thecomplete sequence may, according to some embodiments, take up to twentyseconds. Once the data points are analyzed and the appropriate verticaldeflector positions are determined, the adjustment of the beam toproduce extracted beams with varying beam currents (and thus, intensity)can be performed automatically and rapidly. Based on this plotted curve,the beam current can be subsequently adjusted within milliseconds (e.g.,600 ms), such that the beam currents corresponding to various layers ina treatment plan for a patient—that is, the depths desired within atarget subject according to a proton treatment plan—can be generated bydetermining, on the analyzed suppression curve, the configurations ofthe electrostatic vertical deflector which correspond to the desiredbeam currents. Thus, once steps 601-607 are performed, a protontreatment plan comprised of multiple layers in a target patient may betreated with a single generated proton beam by automatically producingvarying extracted beams with beam currents corresponding to each of thelayers over a wide dynamic range by changing the voltage setting of thevertical deflector to allow efficient, versatile, and adjustable protonradiation treatments.

What is claimed is:
 1. A proton therapy system, the proton therapysystem comprising: a cyclotron, the cyclotron comprising: a plurality ofsub-systems collectively used to operate the cyclotron, the plurality ofsub-systems including at least one sub-system from the group consistingof: a magnet sub-system; a cooling sub-system; a vacuum sub-system; aradio frequency sub-system; a beam injection sub-system, an ion sourcefor producing a proton treatment beam having a beam current; a pluralityof beam path modulators; and a plurality of beam current modulators,wherein, the proton treatment beam is directed by at least one of theplurality of beam path modulators such that at least a portion of theproton treatment beam travels through at least one of the plurality ofbeam current modulators.
 2. The system according to claim 1, wherein theplurality of beam path modulators comprises a plurality of electrostaticdeflectors.
 3. The system according to claim 2, wherein the plurality ofbeam path modulators comprises a collimator.
 4. The system according toclaim 1, wherein the plurality of beam current modulators comprises aplurality a moveable slits.
 5. The system according to claim 2, whereinthe plurality of beam path modulators configurably directs at least aportion of the beam of protons through the plurality of beam currentmodulators by generating an electric field in theelectrostatic-deflector.
 6. The system according to claim 5, wherein theplurality of beam path modulators configurably directs at least aportion of the beam of protons through the plurality of beam currentmodulators by causing a deflection in a trajectory of the beam ofprotons.
 7. The system according to claim 6, wherein the deflection inthe trajectory of the beam of protons is caused by the generatedelectric field in a beam path modulator of the plurality of beam pathmodulators.
 8. The system according to claim 1, wherein a plurality ofextracted proton beams is generated from the proton treatment beam andapplied to a plurality of target treatment layers disposed in a protontherapy patient.
 9. The system according to claim 8, wherein theplurality of target treatment layers comprise target layers with varyingdepths in the proton therapy patient, and wherein the varying depthscorrespond to a treatment plan for the proton therapy patient.
 10. Thesystem according to claim 8, wherein the plurality of extracted protonbeams is generated by attenuating the beam current of the protontreatment beam to correspond to the plurality of target treatmentlayers.
 11. The system according to claim 10, wherein the attenuatingthe beam current is performed by directing varying portions of theproton treatment beam through the plurality of beam current modulatorsaccording to pre-determined measurement data.
 12. The system accordingto claim 11, wherein the pre-determined measurement data comprises adata curve which plots a correspondence between a plurality of extractedbeam currents generated from attenuating the beam current of the protontreatment beam and a voltage in the plurality of beam path modulators.13. The system according to claim 12, wherein a proton therapy treatmentcomprising a plurality of extracted beam currents corresponding to aplurality of target treatment layers is generated by the system andapplied to a proton therapy patient by automatically attenuating thebeam current of the proton therapy treatment beam according tomeasurement data comprised in the data curve.
 14. A method for applyingproton therapy comprising: entering a plurality of power states for aplurality of sub-systems in a cyclotron; generating a beam of protonsfrom an ion source comprised in the cyclotron, the beam of protonshaving a beam current; directing, via a plurality of beam pathmodulators comprised in the cyclotron, the beam of protons through aplurality of beam current modulators; conducting a plurality of beamcurrent measurements by performing a plurality of beam currentadjustments; analyzing the plurality of beam current measurements todetermine a plurality of settings for the plurality of beam pathmodulators; and automatically producing a plurality of desired beamcurrents by adjusting the plurality of beam path modulators to modifythe beam current to conform to the plurality of pre-determinedconfigurations.
 15. The method according to claim 14, wherein theplurality of pre-determined configurations correspond to a protontherapy treatment plan for a proton therapy patient.
 16. The methodaccording to claim 14, wherein the generating, the directing, theconducting, the analyzing and the producing are performed in acyclotron.
 17. The method according to claim 14, wherein the pluralityof beam path modulators comprises a plurality of deflector plates. 18.The method according to claim 17, wherein the plurality of beam pathmodulators comprises a collimator.
 19. The method according to claim 14,wherein the plurality of beam current modulators comprises a pluralityof moveable slits.
 20. The method according to claim 14, wherein thedirecting the beam of protons through a plurality of beam currentmodulators is performed by modifying openings of the beam currentmodulators.
 21. The method according to claim 20, wherein automaticallyproducing the plurality of desired beam currents comprises adjusting aconfiguration of the plurality of beam path modulators to modify thetrajectory of the beam of protons such that only a portion of the beamof protons passes through the plurality of beam current modulators. 22.The method according to claim 21, wherein the modifying the trajectoryof the beam of protons is performed by generating a voltage in theplurality of beam path modulators.
 23. The method according to claim 22,wherein the adjusting a plurality of beam path modulators to modify thetrajectory of the beam of protons such that only a portion of the beamof protons passes through the plurality of beam current modulatorscomprises producing an extracted beam of protons having a beam currentcorresponding to the portion of the beam of protons which passed throughthe plurality of beam current modulators.
 24. The method according toclaim 15, wherein the performing a plurality of beam current adjustmentsto conduct a plurality of beam current measurements comprises:configuring the plurality of beam path modulators according to theplurality of pre-determined configurations; and measuring the beamcurrents of the proton beam produced when the plurality of beam pathmodulators is configured according to the plurality of pre-determinedconfigurations.
 25. The method according to claim 24, wherein theanalyzing the plurality of beam current measurements comprises:measuring beam currents of the proton beam produced when the pluralityof beam path modulators is configured according to the plurality ofpre-determined configurations; and extrapolating the measured beamcurrents to generate a curve.
 26. The method according to claim 25,wherein the automatically producing the plurality of desired beamcurrents comprises: receiving the plurality of desired beam currents,the plurality of desired beam currents corresponding to a plurality oftarget layers in the proton therapy patient; and determining, on thegenerated curve, a plurality of beam path modulator configurations thatcorrespond to the plurality of desired beam currents corresponding tothe plurality of target layers in the proton therapy patient.
 27. Themethod according to claim 26, wherein the plurality of target layers ina treatment target comprises a plurality of target layers with varyingdepths disposed in the proton therapy patient.
 28. The method accordingto claim 27, wherein the plurality of target layers with varying depthscorrespond to a proton therapy plan of the proton therapy patient. 29.The method according to claim 25, wherein the automatically producingthe plurality of desired beam currents comprises adjusting the pluralityof beam path modulators to conform to the plurality of beam pathmodulator configurations that correspond to the plurality of desiredbeam currents.
 30. A cyclotron, comprising: a plurality of sub-systemscollectively used to operate the cyclotron, the plurality of sub-systemsincluding at least one sub-system from the group consisting of: a magnetsub-system; a cooling sub-system; a vacuum sub-system; a radio frequencysub-system; a beam infection sub-system, a ion source for producing abeam of protons, the beam of protons having a trajectory and a beamcurrent; a plurality of electrostatic vertical deflectors with acorresponding vertical collimator for causing a deflection of atrajectory of the beam of protons; a plurality of phase slits foradjusting a beam current of the beam of protons; a measuring device formeasuring the beam current of a beam of protons produced by the ionsource and extracted through the plurality of phase slits, wherein, thecyclotron is used to perform a proton beam therapy treatment byautomatically applying a plurality of beam currents to a target patient,the plurality of beam currents being generated by deflecting, via theplurality of electrostatic vertical deflectors, the trajectory of thebeam of protons through the plurality of the vertical collimators andthe plurality of phase slits.